Files
Jyotisha/frontend/src/lib/report-chart-grid-rehype.ts
T

128 lines
3.7 KiB
TypeScript

const CHART_HEADING_RE = /^(?:D\d{1,3}\b|Moon Chart)/;
type HastProperties = {
className?: string | string[] | null;
[key: string]: unknown;
};
type HastNode = {
type: string;
tagName?: string;
value?: string;
properties?: HastProperties;
children?: HastNode[];
};
type HastRoot = {
type: "root";
children: HastNode[];
};
function classNames(node: HastNode | undefined): string[] {
const value = node?.properties?.className;
if (Array.isArray(value)) return value.map(String);
if (typeof value === "string") return value.split(/\s+/).filter(Boolean);
return [];
}
function hasClass(node: HastNode | undefined, name: string): boolean {
return classNames(node).includes(name);
}
function isWhitespace(node: HastNode | undefined): boolean {
return Boolean(node && node.type === "text" && !String(node.value ?? "").trim());
}
function flattenText(node: HastNode | undefined): string {
if (!node) return "";
if (node.type === "text") return String(node.value ?? "");
if (!Array.isArray(node.children)) return "";
return node.children.map(flattenText).join("");
}
function isElement(node: HastNode | undefined, tagName: string): node is HastNode {
return Boolean(node && node.type === "element" && node.tagName === tagName);
}
function isChartHeading(node: HastNode | undefined): boolean {
return isElement(node, "h4") && CHART_HEADING_RE.test(flattenText(node).trim());
}
function isChartPre(node: HastNode | undefined): boolean {
if (!isElement(node, "pre") || !Array.isArray(node.children)) return false;
const code = node.children.find((child) => isElement(child, "code"));
return hasClass(code, "language-jyotish-chart") || hasClass(code, "jyotish-chart");
}
function skipWhitespace(nodes: readonly HastNode[], index: number): number {
let cursor = index;
while (cursor < nodes.length && isWhitespace(nodes[cursor])) cursor += 1;
return cursor;
}
function element(tagName: string, className: string[], children: HastNode[]): HastNode {
return {
type: "element",
tagName,
properties: { className },
children,
};
}
function parseCard(nodes: readonly HastNode[], index: number): { card: HastNode; next: number } | null {
const heading = nodes[index];
if (!isChartHeading(heading)) return null;
const children: HastNode[] = [heading];
let cursor = skipWhitespace(nodes, index + 1);
if (isElement(nodes[cursor], "p")) {
const afterParagraph = skipWhitespace(nodes, cursor + 1);
if (isChartPre(nodes[afterParagraph])) {
children.push(nodes[cursor] as HastNode);
cursor = afterParagraph;
}
}
if (!isChartPre(nodes[cursor])) return null;
children.push(nodes[cursor] as HastNode);
return {
card: element("div", ["personal-report-chart-card"], children),
next: cursor + 1,
};
}
export function groupReportChartNodes(nodes: readonly HastNode[]): HastNode[] {
const grouped: HastNode[] = [];
let index = 0;
while (index < nodes.length) {
const first = parseCard(nodes, index);
if (!first) {
grouped.push(nodes[index] as HastNode);
index += 1;
continue;
}
const cards = [first.card];
index = first.next;
while (index < nodes.length) {
const peeked = skipWhitespace(nodes, index);
const next = parseCard(nodes, peeked);
if (!next) break;
cards.push(next.card);
index = next.next;
}
grouped.push(element(
"div",
cards.length === 1
? ["personal-report-chart-grid", "is-single"]
: ["personal-report-chart-grid"],
cards,
));
}
return grouped;
}
export function reportChartGrid() {
return function groupReportCharts(tree: HastRoot) {
if (tree?.type !== "root" || !Array.isArray(tree.children)) return;
tree.children = groupReportChartNodes(tree.children);
};
}